Abstract: An earphone microphone is constituted of a main unit and an insert portion which are united in an L-shape. Two receivers are attached to the external surface of the main unit and exposed externally of a user's ear, whilst one receiver is attached to a distal end of the insert portion that is inserted into a user's external auditory canal and disposed opposite to a user's eardrum. A signal processor produces a difference signal between the output signals of two receivers exposed externally of the user's ear. The difference signal is subjected to high-pass filtering and subsequently added to the output signal of the receiver disposed inside the user's external auditory canal, thus producing a sound signal representing a user's sound. The sound signal includes a sufficient number of frequency components (e.g. frequency components higher than 3 kHz) prerequisite for discriminating the user's sound.

Abstract: On a casing of an electronic keyboard instrument, there are provided front speakers, rear speakers and upper speakers as non-front speakers, a woofer speaker, and a vibrator. Tone generator section generates tone signals of tone colors corresponding to tones of various musical instruments. Assignment section adjusts, on a tone-color-by-tone-color basis, tone volume allocations, of the generated tone signals, to the speakers and vibrator. Further, the thus-adjusted tone signals are mixed for each of speaker reproduction systems and vibrator drive system, and then the resultant mixed tone signals of the speaker reproduction systems and vibrator drive system are supplied to corresponding ones of the speakers and vibrator.

Abstract: On a casing of an electronic keyboard instrument, there are provided front speakers, rear speakers and upper speakers as non-front speakers, a woofer speaker, and a vibrator. Tone generator section generates tone signals of tone colors corresponding to tones of various musical instruments. Assignment section adjusts, on a tone-color-by-tone-color basis, tone volume allocations, of the generated tone signals, to the speakers and vibrator. Further, the thus-adjusted tone signals are mixed for each of speaker reproduction systems and vibrator drive system, and then the resultant mixed tone signals of the speaker reproduction systems and vibrator drive system are supplied to corresponding ones of the speakers and vibrator.